Are earthquakes at Yellowstone related to volcanism?
Earthquakes, volcanism, and hydrothermal features go hand in hand at Yellowstone. The underground plumbing of hot water and magmas beneath Yellowstone is influenced by the same stresses that cause earthquakes. The largest historic earthquake in the Rocky Mountains occurred in the Yellowstone region. The magnitude 7.5 earthquake northwest of the National Park in 1959 was caused by the extension or stretching of the Earth’s crust. The earthquake caused the land to rupture, displacing a 40-km-long fault that rose vertically up to 20 feet. The same stretching of the Earth’s crust that caused the 1959 earthquake causes a reduction in the horizontal pressures on Yellowstone’s magma systems, allowing them easier ascent through the crust. Thus, when earthquakes occur in or around Yellowstone, they can change the stress on hydrothermal and magma reservoirs, leading to enhanced fluid movement. Conversely, volcanic processes can induce earthquakes.
